Articulation joint with bending member

ABSTRACT

The present disclosure provides an articulation joint that can include a plurality of articulation links, wherein each articulation link can include an elongate body having a proximal end, a distal end, an outer surface, and a first lumen extending from the proximal end to the distal end. Each articulation link can further include a plurality of arms extending radially outward from the elongate body, wherein each arm includes an inner end attached to the outer surface of the elongate body and a second lumen extending from a proximal side of the arm to a distal side of the arm. The articulation joint can also include a bending member positioned within the first lumen of the elongate body and a control member positioned within a plurality of second lumens, wherein each of the plurality of second lumens includes a common longitudinal axis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/961,301, filed on Aug. 7, 2013, which claims the benefit of priorityfrom U.S. Provisional Application No. 61/694,371, filed on Aug. 29,2012, all of which are herein incorporated by reference in theirentireties.

TECHNICAL FIELD

The following disclosure relates generally to medical devices and inparticular to articulation joints for use with steerable medicaldevices.

BACKGROUND

As an alternative to performing more invasive surgical procedures, manyphysicians use minimally invasive medical devices to diagnose and treatpatients. A minimally invasive medical device, such as an endoscope or acatheter, often has an elongate shaft that is inserted into the patient.The shaft can include one or more channels through which an instrumentcan be placed to access a site within the patient.

In order to guide the medical device to a desired location, the shaftcan include one or more control members that may be controlled by anactuator located proximally along the device. By tensioning a controlmember, the shaft's distal tip can be bent in a desired direction. Tofacilitate this bending, the medical device can include an articulationjoint located along the shaft or at the distal end of the device. Thearticulation joint is designed to permit bending of the shaft in adesired direction, whereby bending can be controlled by applying a forceto one or more control members.

Most articulation joints found in steerable medical devices are madefrom stainless steel or other biocompatible materials. These devices canbe expensive to manufacture and may have to withstand repeatedsterilizations or cleanings. Despite these precautions, contaminants ordisease may be passed from one patient to another. To reduce the risk ofcross-patient contamination and to lower the cost of minimally invasiveprocedures, more affordable medical devices require development.

The present disclosure relates to improvements in an articulation jointfor steerable medical devices that addresses at least some of thelimitations of the prior art.

SUMMARY

According to one aspect of the present disclosure, an articulation jointcan include a plurality of articulation links, wherein each articulationlink can include an elongate body having a proximal end, a distal end,an outer surface, and a first lumen extending from the proximal end tothe distal end. Each articulation link can further include a pluralityof arms extending radially outward from the elongate body, wherein atleast one arm of the plurality of arms includes a first end coupled tothe outer surface of the elongate body and a second lumen. Thearticulation joint can also include a control member positioned withinthe second lumen.

In addition, the articulation joint may include one of more of thefollowing features: an articulation link of the plurality ofarticulation links may include a support member fixedly attached to asecond end of the at least one arm, the second lumen may include alongitudinal axis that may be transverse to a longitudinal axis of theat least one arm, an articulation link of the plurality of articulationlinks may include a contact surface configured to engage an adjacentarticulation link to permit relative movement between the articulationlink and the adjacent articulation link, wherein the contact surfaceincludes at least one of a camming surface, a pivoting surface, aconcave surface, and a convex surface, at least one of the plurality ofarticulation links may have a central longitudinal axis of the firstlumen located asymmetrically relative to a central longitudinal axis ofthe at least one of the plurality of articulation links, a bendingmember positioned within the first lumen of the elongate body, whereinthe bending member may include at least one of an elastomeric rod andspring, the spring may include a lumen configured to receive a medicaldevice, the arms may be distributed symmetrically about the outersurface of the elongate body and define a region configured to receive amedical device, the plurality of articulation links may be positionedapart along a longitudinal axis such that the proximal end of a firstarticulation link and the distal end of a second articulation linklocated adjacent to the first articulation link are separated by alength of a bending member, and each of the second lumens may include acommon longitudinal axis.

According to another aspect of the present disclosure, an articulationlink can include an elongate body having a proximal end, a distal end,an outer surface, and a first lumen extending from the proximal end tothe distal end, wherein the first lumen is configured to receive abending member. The articulation link can also include a plurality ofarms extending outward from the outer surface of the elongate body, eacharm including an outer end having a second lumen extending from aproximal side of the arm to a distal side of the arm, the second lumenbeing configured to receive a control member.

According to yet another aspect of the present disclosure, anarticulating medical device can include a plurality of articulationlinks, wherein each articulation link includes an elongate body having alongitudinal axis and a first lumen. Each articulation link can alsoinclude a plurality of arms extending transverse to the longitudinalaxis and outward from the elongate body, each arm including a secondlumen. The articulating medical device can also include a control memberpositioned within a plurality of second lumens, and a cover locatedabout the plurality of articulation links.

Additional objects and advantages of the invention will be set forth inpart in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention will be realized and attained bymeans of the elements and combinations particularly pointed out in theappended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description, serve to explain the principles of theinvention.

FIG. 1 is a perspective view of a device, according to an exemplaryembodiment of the invention;

FIG. 2 illustrates an articulation joint, according to an exemplaryembodiment of the invention;

FIG. 3 illustrates a plan view of one embodiment of an articulationlink, in accordance with the disclosed technology;

FIG. 4 illustrates a bent articulation joint, according to an exemplaryembodiment of the invention;

FIG. 5 illustrates another embodiment of an articulation joint,according to an exemplary embodiment of the invention;

FIG. 6 illustrates another articulation joint, according to an exemplaryembodiment of the invention;

FIG. 7 illustrates a plan view of a link of an articulation joint havingno support member, according to an exemplary embodiment of theinvention; and

FIG. 8 illustrates a plan view of a link of an articulation joint havingan eccentric center channel, according to an exemplary embodiment of theinvention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made to exemplary embodiments of the invention,examples of which are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts.

FIG. 1 depicts a device 2, according to an exemplary embodiment. Device2 can include a medical device configured for use with a surgicalmethod, including a therapeutic or diagnostic procedure. Device 2 caninclude an endoscope, a guide tube, a catheter, a guidewire, or othertype of elongate medical device. In some embodiments, device 2 caninclude a flexible instrument, such as, for example, a grasper, adissector, scissors, a stapler, an electrosurgical device, or other typeof endoscopic or laparoscopic instrument. Further, device 2 may be usedfor procedures within or adjacent to various body organs, such as, anesophagus, a heart, a stomach, a pelvic area, a bladder, an intestine,or a gastrointestinal, urinary, or pulmonary tract.

Device 2 may be configured for insertion into a patient's body throughan anatomical opening. In other embodiments, device 2 may be used innatural orifice transluminal endoscopic surgery (NOTES) procedures orsingle incision laparoscopic surgical (SILS) procedures. Accordingly,device 2 can be shaped and sized for placement into a patient via a bodycavity or an incision.

Device 2 can be configured to operate with one or more instruments (notshown) used in various surgical procedures. For example, device 2 caninclude one or more lumens (not shown) configured to receive a grasper,a pair of scissors, a hook, an ablation device, or other type ofsurgical instrument. Device 2 may also be configured to operate with, orinclude, insufflation, irrigation, suction, imaging, or systems used inendoscopic, laparoscopic, or other surgical procedures.

Device 2 can include a shaft 4 having a proximal end 6 and a distal end8. Proximal end 6 can be manipulated by an operator to control distalend 8. For example, proximal end 6 can include one or more knobs, dials,levers, triggers, handles, or other devices (not shown) configured tomove distal end 8 relative to proximal end 6.

Shaft 4 can also include an articulating portion 9. As shown in FIG. 1,articulating portion 9 can be located at or near distal end 8. In otherembodiments, articulating portion 9 can be located anywhere along shaft4, or encompass the entire length of shaft 4. In operation, an operatorcan manipulate articulation portion 9 to move distal end 8 up, down,left, or right. As indicated above, the disclosed technology relates toimprovements in an articulation joint for a steerable medical device.

According to some exemplary embodiments, articulation portion 9 can beconfigured to provide axial stiffness based on one or more structureslocated generally at or about a central region of articulation portion9. For example, a central part of articulation portion 9 can beconfigured to provide most of the axial stiffness of articulationportion 9 while an outer part of articulation portion 9 may provide lessaxial stiffness than that provided by the central part of articulationportion 9. For example, as described below and shown in FIG. 7, abending member 225 may be configured to provide more axial stiffnessthan the axial stiffness provided by a cover 220. An axially stiffcenter may not add significant bending stress to articulation portion 9,permitting lower bending stiffness.

As described below in more detail, a central part of articulationportion 9 may be configured to provide a major part of the load bearingfor an articulation mechanism under tension. In addition to providing atleast the majority of compressive load bearing, the central part mayalso provide a pivoting axis for articulation portion 9. Articulationportion 9 may also include an outer part that provides little or nocompression strength. Accordingly, the outer part may be formed from lowcost, low durometer plastic, or low durometer braid. Various embodimentsof articulation portion 9 are described as follows.

FIG. 2 illustrates an articulation joint 10 in accordance with oneembodiment of the disclosed technology. Articulation joint 10 caninclude a number of articulation links 12, 14, 16, 18. Each articulationlink can include an elongate body 20 having a first lumen 23 (see FIG.3) that can be configured to receive a bending member 125. Elongate body20 can be cylindrical or another shape, and may include a longitudinalaxis 19 extending along the length of elongate body 20.

Bending member 125 can be configured to flex to permit relative movementbetween articulation links 12-18. For example, bending member 125 caninclude a spring 34 (see FIG. 2), an elastomeric rod 127 (see FIG. 4),or another type of elastic member that may be located within first lumen23. In some embodiments, spring 34 may be tightly wound or more looselywound depending on the desired stiffness, looseness, or compressibilityof articulation joint 10. To retain bending member 125 in articulationlinks 12-18, one or more elongate bodies 20 may be fixedly coupled tobending member 125. For example, a proximal-most or a distal-mostelongate body 20 can be fixedly attached to bending member 125 by afriction fit, crimping, welding, adhesive, or another joining method.

As shown in FIGS. 2 and 3, elongate body 20 can also include a distalend 40, a proximal end 42, and an outer surface 44. As explained below,distal end 40 of articulation link 14 may be configured to moveablyengage proximal end 42 of a proximally-located adjacent articulationlink 12. This relative movement can permit selective bending ofarticulating portion 9.

As shown in FIGS. 2 and 3, each articulation link 12-18 can also includetwo or more arms 22 a, 22 b, 22 c and 22 d that may extend radiallyoutwards from elongate body 20. Specifically, arm 22 may extend outwardsfrom an outer surface 44 of elongate body 20. In the embodiments shownherein, each articulation link 12-18 has four radially extending arms 22a-22 d equally spaced about elongate body 20. However, it will beappreciated that a greater or lesser number of arms 22 a-22 d, andunequal arm spacing, could be used. For example, some articulation links12-18 may include two arms 22 while others may have three or more arms22.

As shown in FIG. 3, each of the outer ends of the arms 22 a-22 d caninclude, respectively, a second lumen 24 a-24 d. Second lumen 24 canalso be located anywhere along arm 22. Further, second lumens 24 a-24 dcan be aligned generally parallel to longitudinal axis 19 of elongatebody 20. Moreover, each second lumen 24 a-24 d of articulation link 12may be in longitudinal alignment with corresponding second lumens 24a-24 d of other articulation links 14-18. Because second lumen 24 can beconfigured to receive a control member 30, aligning second lumens 24a-24 d along common longitudinal axes allows for placement of controlmembers 30 a-30 d through the commonly aligned second lumens 24 a-24 d.The second lumens 24 a-24 d may be positioned away from the pivotingaxis.

As shown in FIG. 2, a single control member 30 can be positioned withina plurality of corresponding second lumens 24 a-24 d located on aplurality of articulation links 12-18. Each set of corresponding secondlumens 24 a-24 d, stacked longitudinally and aligned on a commonlongitudinal axis, can receive a common control member 30 a-30 d. Forexample, control member 30 a can pass through a plurality of secondlumens 24 a, wherein each second lumen 24 a is generally aligned along acommon longitudinal axis 31 a. Similarly, control member 30 b can passthrough corresponding second lumens 24 b on at least articulation links12-18, wherein each second lumen 24 b is generally aligned along acommon longitudinal axis 31 b.

Longitudinal axes 31 a and 31 b can be parallel and laterally displacedfrom each other or from longitudinal axis 19. Thus, when articulationjoint 10 is in a generally straight configuration, control members 30a-d can be generally parallel to each other. As such, control members 30a-d can have longitudinal axes 31 a-d that are generally parallel to andlaterally displaced from each other.

In operation, a single control member 30 can pass freely through one ormore articulation links 12-18 to selectively move articulation joint 10.One or more control members 30 may extend through shaft 4 and terminateat a distal region of shaft 4, for example, at a most distal link. Insome embodiments, a handle, lever, dial, or control knob can be moved toselectively tension one or more control members 30 to steer distal end 8of shaft 4 in a desired direction.

Control member 30 can include a wire, a cable, a ribbon, a rod, or anysuitable elongate member. Control member 30 can include a distal end, astop, a loop, or other mechanism that secures it to a distal-most or aproximal-most articulation link so that it does not pull througharticulation links 12-18. It is also contemplated that at least part ofcontrol member 30 can include an outer sheath and an inner core wire. Insome embodiments, the outer sheath can be sized to frictionally engagesecond lumen 24 of articulation link 12, a distal-most articulationlink, or a proximal-most articulation link.

In the embodiment shown in FIGS. 2 and 3, a support member 26 extendsgenerally around the outer ends of the arms 22 a-22 d. Support member 26may be configured to provide rigidity to one or more arms 22, such as,for example, torsional rigidity. Also, support member 26 may extendbetween two or more arms 22 and may be any suitable shape, such as, forexample, a radial hoop. In some embodiments, support member 26 mayinclude a straight member or may extend generally from a mid-point ofone or more arms 22.

As shown in FIG. 3, articulation link 12 can include a number of spaces28 a-28 d in the areas between arms 22 a-22 d. A tube, shaft, wire, orother component of a medical instrument could be routed through spaces28 a-28 d. It is also contemplated that a working channel or otherelongate structure could be routed through the center of first lumen 23within bending member 125. For example, one or more flexible endoscopicinstruments could be passed through lumen 23 and/or spaces 28 a-28 d.

To permit movement of articulation joint 10, articulation links 12-18may include one or more contact surfaces configured to permit relativemovement between articulation links 12-18. A contact surface may also beconfigured to reduce or prevent adjacent articulation links 12-18 fromrotating about longitudinal axis 19 with respect to each other whileallowing deflection from longitudinal axis 19. For example, FIG. 4 showsa bent articulation joint 10 deviating from longitudinal axis 19.

In one embodiment, a contact surface can include a concave or a convexsurface. As shown in FIG. 4, articulation link 14 can include one ormore convex surfaces 32 located at proximal end 42 of elongate body 20that fit within corresponding one or more concave surfaces 34 located atdistal end 43 of articulation link 12. Articulation link 14 can alsoinclude a second contact surface 38 located at the distal end 40 ofelongate body 20.

In the embodiment shown in FIG. 4, contact surface 32 and contactsurface 38 at each end of elongate body 20 are offset and rotated aboutthe longitudinal axis by 90° with respect to each other. Such an offsetof contact surfaces permits adjacent articulation links to pivot indifferent directions relative to each other, wherein each direction isoffset by 90° relative to the other. This allows, for example,left-right and up-down movement of articulation joint 10. Otherembodiments can include no offset or a different angle of offset.

In other embodiments, articulation link 12 can include one or morepivoting surfaces (not shown). Pivoting surfaces can include a joint ora hinge configured to allow pivoting between adjacent articulationlinks. Other types of couplings between articulation links 12-18 arealso possible. For example, contact surfaces can include a ball andsocket type coupling, whereby the “ball” contact surface of anarticulation link couples with corresponding “socket” contact surface onan adjacent articulation link.

In contrast to the embodiments shown above, the adjacent articulationlinks shown in FIG. 5 are joined by a flexible section 370. Inparticular, an articulation joint 350 has a number of articulation links352-358. As shown, each articulation link 352-358 includes an elongatebody 360, a spring 365 extending therethrough, and a number of radialarms with lumens for receiving a control member, as previouslydescribed. Flexible section 370 can include a living hinge formed usinga plastic material. In some embodiments, a V-shaped notch may providesufficient flexibility to operate as a hinge-like device. For examplecutouts 372 and 374 located on either side of flexible section 370 candefine the extent of bending that can occur between adjacentarticulation links. Adjacent flexible sections 370 can also bealternating in their alignment and offset by 90°, as shown.

FIG. 6 illustrates another alternative embodiment of an articulationjoint 210. Specifically, articulation joint 210 includes a number ofarticulation links 202, 204, and 206 that are physically separated alonga longitudinal axis 219. Separating articulation links 202-206 canpermit greater flexibility of articulation joint 210, reduce wear toarticulation links 202-206, or simplify manufacture of articulationjoint 210.

FIGS. 6 and 7 show an elongate body 215 having a first lumen 223extending therethrough and surrounding bending member 225. Articulationlink 202 can also include various numbers of arms 212. As shown in FIG.7, articulation link 202 includes four arms 212 a-212 d extendingradially outward from an outer surface 244 of elongate body 215. Theouter ends of arms 212 a-212 d include second lumens 224 a-224 dconfigured to receive control members 230 a-230 d. As previouslyexplained, although FIGS. 6 and 7 show four radially extending arms 212a-212 d, a lesser or greater number of arms could be included depending,for example, upon the number of control members 230 a-d.

In contrast to the embodiments shown above, articulation links 202-206do not include any support structure connecting two or more arms 212a-212 d. Cover 220 can extend about one or more articulation links202-206. As described above, the spaces between arms 212 a-212 d andcover 220 may define a number of spaces 228 a-228 d. Cover 220 may aidin transmitting torque along the length of articulation joint 210 orform a protective outer surface of articulation joint 210. Cover 220 mayinclude a braid, a wire, a mesh, or other material that may aid intransmitting torque along articulation joint 210.

FIG. 8 is a cross-sectional view of a single articulation link 112,according to another exemplary embodiment. As shown, articulation link112 can include an elongate body 120 having a first lumen 123 and anumber of radially extending arms 122 a-122 d, wherein each arm caninclude a second lumen 124 a-124 d. As explained above, control members(not shown) can be passed through one or more second lumens 124 a-124 dand support member 126 may link the outer ends of the arms 122 a-122 d.

In the embodiment shown, elongate body 120 and lumen 123 areasymmetrically located from the center of articulation link 112. Thatis, elongate body and lumen 123 are centered on a longitudinal axis thatis offset with respect to the central longitudinal axis of articulationlink 112. This can permit preferential bending in a single direction ofan articulation joint formed from such articulation links 112. In theembodiment shown in FIG. 8, articulation link 112 can bend more easilyin the direction of arm 122 d due to the greater length of the arm 122 dwith respect to the remaining arms 122 a-122 c.

The embodiments described herein are exemplary only, and it will beapparent to those skilled in the art that various modifications andvariations can be made in the disclosed systems and processes withoutdeparting from the scope of the invention. Other embodiments of theinvention will be apparent to those skilled in the art fromconsideration of the specification and practice of the inventiondisclosed herein. It is intended that the specification and examples beconsidered as exemplary only, with a true scope of the invention beingindicated by the following claims.

We claim:
 1. An articulation assembly, comprising: a sheath; anarticulation link within the sheath, wherein the articulation linkincludes a central passage, wherein surface portions of the articulationlink define one or more sides of a peripheral passage, the peripheralpassage being radially outward of the central passage, and wherein theperipheral passage includes curved sides and straight sides; and a lumenconfigured to receive a control member; wherein a surface portion of thesheath defines one of the curved sides of the peripheral passage, andwherein at least one of the curved sides of the peripheral passage isformed by a wall of the lumen.
 2. The articulation assembly of claim 1,wherein the surface portions of the articulation link define (a) atleast one of the curved sides and (b) the straight sides of theperipheral passage.
 3. The articulation assembly of claim 1, wherein thearticulation link includes a cylindrical portion defining the centralpassage.
 4. The articulation assembly of claim 3, wherein thearticulation link includes a pair of straight surface portions extendingradially-outwardly from the cylindrical portion, wherein the peripheralpassage extends between the pair of straight surface portions, andwherein the pair of straight surface portions define the straight sidesof the peripheral passage.
 5. The articulation assembly of claim 4,wherein the articulation link includes a peripheral cylindrical portionat an end of a straight surface portion of the pair of straight surfaceportions.
 6. The articulation assembly of claim 1, wherein the curvedsides of the peripheral passage include a radially-inner convex side anda radially-outer concave side.
 7. The articulation assembly of claim 1,further including a bendable member extending through the centralpassage, wherein the articulation link is one of a plurality ofarticulation links mounted on the bendable member.
 8. The articulationassembly of claim 7, wherein adjacent articulation links of theplurality of articulation links have opposing surfaces separated by agap, and wherein the bendable member is exposed at the gap.
 9. Thearticulation assembly of claim 1, wherein one side of the peripheralpassage is defined by a wall of the central passage.
 10. Thearticulation assembly of claim 1, wherein the at least one curved sideformed by the wall of the lumen is between a curved side of theperipheral passage and a straight side of the peripheral passage.
 11. Anarticulation assembly, comprising: a sheath; a bendable member withinthe sheath; a plurality of articulation links within the sheath, whereinthe plurality of articulation links are mounted on the bendable membersuch that a central passage of each of the plurality of articulationlinks surrounds a portion of the bendable member, wherein adjacentarticulation links of the plurality of articulation links have opposingsurfaces separated by a gap, and wherein the bendable member is exposedat the gap between the opposing surfaces of the adjacent articulationlinks; wherein surface portions of each of the plurality of articulationlinks define one or more sides of a peripheral passage, the peripheralpassage being radially outward of the central passage, and wherein theperipheral passage includes curved sides and straight sides.
 12. Thearticulation assembly of claim 11, wherein an inner surface at least onearticulation link of the plurality of articulation links is fixedlycoupled to an outer surface of the bendable member.
 13. The articulationassembly of claim 11, wherein the opposing surfaces extend parallel toeach other when the bendable member is in a straight configuration. 14.The articulation assembly of claim 11, wherein a surface portion of thesheath defines one of the curved sides of the peripheral passage. 15.The articulation assembly of claim 14, wherein one side of theperipheral passage is defined by a wall of the central passage.
 16. Thearticulation assembly of claim 11, wherein each of the plurality ofarticulation links includes a lumen configured to receive a controlmember, wherein at least one of the curved sides of the peripheralpassage is formed by a wall of the lumen.
 17. The articulation assemblyof claim 16, wherein the at least one curved side formed by the wall ofthe lumen is between a curved side of the peripheral passage and astraight side of the peripheral passage.
 18. The articulation assemblyof claim 11, wherein each of the plurality of articulation links doesnot directly contact another of the plurality of articulation links. 19.An articulation assembly, comprising: a sheath; and an articulation linkwithin the sheath, wherein the articulation link includes a cylindricalportion defining a central passage, wherein surface portions of thearticulation link define one or more sides of a peripheral passage, theperipheral passage being radially outward of the central passage,wherein the peripheral passage includes curved sides and straight sides,wherein the articulation link includes a pair of straight surfaceportions extending radially-outwardly from the cylindrical portion,wherein the peripheral passage extends between the pair of straightsurface portions, wherein the pair of straight surface portions definethe straight sides of the peripheral passage, wherein the articulationlink includes a peripheral cylindrical portion at an end of a straightsurface portion of the pair of straight surface portions, and wherein asurface portion of the sheath defines one of the curved sides of theperipheral passage.